Numerous closing devices for sachets have already been put forward.
The majority of these devices is formed on the basis of complementary male/female profiles, or even hooks or hook and loop fastener-type devices such as those sold under the trademark VELCRO.
Numerous slider structures for controlling such closing devices have also been proposed.
The aim of the present invention is to propose novel closing devices with a slider having properties superior to those of known devices.
More precisely, the aim of the present invention is to propose means limiting the risk of the sliders being torn off.
Different attempts have been made for this purpose. However, none of them provides total satisfaction.
The documents US 2005/041892, EP 1153552, EP 1447338 and U.S. Pat. No. 3,426,396 for example describe rigid structures on sliders, intended to be rest on complementary elements provided on the closing devices.
The documents U.S. Pat. No. 6,611,998 and U.S. Pat. No. 6,691,375 describe a solution consisting of placing, on the inner surfaces of the lateral flanges of the sliders flexible lips intended to cooperate with complementary elements provided on the closing devices. The drawback to this solution is forcing the lateral flanges apart when the closing devices stress said flexible lips.
The above aim is achieved within the framework of the present invention due to a closing device for a sachet comprising at least two complementary closing elements and an associated slider comprising a central bead, adapted to modify the joining state of said two elements by respectively separating or engaging the latter according to its direction of motion, characterized in that the slider comprises at least one flexible lip placed on the apex of the central bead opposite a lead angle provided on a closing element, according to a configuration such that any attempt to withdraw the slider results in autolocking hanging of the lip.
“Autolocking hanging” of the lip is understood to mean any reinforcing of the effort exerted on the flexible lip by the lead angle opposite the closing element, tending to reinforce locking of said flexible lip against said lead angle.
As will also be understood within the scope of the present invention since the flexible lip is carried by the apex of the central bead of the slider and not by a lateral flange of the latter, the thrust exerted on the flexible lip is distributed over the central bead and not on the lateral flanges of the slider.
The present invention also concerns sachets equipped with such a closing device.